This invention relates to an improved cutting line head assembly for rotary cutters such as rotary lawn trimmers, mowers, edgers or the like, which employs flexible non-metallic cutting lines.
A cutting line head assembly of this kind is known, e.g. from U.S. Pat. No. 3,826,068, which comprises a rotary body detachably secured to a lower end of a casing of a rotary cutter for rotation about the lower end by drive means such as a flexible cable or shaft, a plurality of spools arranged within the rotary body and wound with respective cutting lines formed of synthetic resin, and a cap attached to the rotary body, the cutting lines having free end portions outwardly extending through windows formed in the peripheral wall of the rotary body so that during rotation of the rotary body driven by the drive means the free end portions of the cutting lines revolve about the rotating rotary body to cut grass such as lawn.
According to this conventional cutting line head assembly, in mounting the assembly onto the casing, the cutting lines are previously wound onto the respective spools, the spools with the cutting lines are placed into the rotary body, and the free end portions of the cutting lines are pulled out of the rotary body through the windows. Then, the cap is attached to the rotary body to complete the assembly. The completed assembly is mounted onto the casing. In addition to these various steps, the operations of placing the spools wound with the cutting lines into the rotary body and guiding the free end portions of the cutting lines through the windows are very difficult to carry out because the gaps between the outer peripheries of the windings of cutting lines and the inner peripheral wall of the rotary body are very narrow. Moreover, these difficult operations are indispensable whenever the cutting lines become exhausted, thus rendering it difficult to supplement new cutting lines. Still further, since the cutting lines are manually wound onto the spools by the operator, the resulting windings can be uneven, which may cause unsmooth paying-out of the cutting lines.